Incentive module simulations (#439)

* Incentive module simulations (#439)
Co-authored-by: John Maheswaran <jmaheswaran@users.noreply.github.com>
Co-authored-by: Kevin Davis <karzak@users.noreply.github.com>
Co-authored-by: Kevin Davis <kjydavis3@gmail.com>
Co-authored-by: John Maheswaran <john@kava.io>

app/app.go

@@ -333,7 +333,7 @@ func NewApp(logger log.Logger, db dbm.DB, traceStore io.Writer, loadLatest bool,
 		pricefeed.NewAppModule(app.pricefeedKeeper, app.accountKeeper),
 		bep3.NewAppModule(app.bep3Keeper, app.accountKeeper, app.supplyKeeper),
 		kavadist.NewAppModule(app.kavadistKeeper, app.supplyKeeper),
-		incentive.NewAppModule(app.incentiveKeeper, app.supplyKeeper),
+		incentive.NewAppModule(app.incentiveKeeper, app.accountKeeper, app.supplyKeeper),
 	)
 
 	// During begin block slashing happens after distr.BeginBlocker so that
@@ -376,7 +376,7 @@ func NewApp(logger log.Logger, db dbm.DB, traceStore io.Writer, loadLatest bool,
 		auction.NewAppModule(app.auctionKeeper, app.accountKeeper, app.supplyKeeper),
 		bep3.NewAppModule(app.bep3Keeper, app.accountKeeper, app.supplyKeeper),
 		kavadist.NewAppModule(app.kavadistKeeper, app.supplyKeeper),
-		incentive.NewAppModule(app.incentiveKeeper, app.supplyKeeper),
+		incentive.NewAppModule(app.incentiveKeeper, app.accountKeeper, app.supplyKeeper),
 	)
 
 	app.sm.RegisterStoreDecoders()

app/params/params.go

@@ -12,4 +12,5 @@ const (
 	DefaultWeightMsgCreateAtomicSwap int = 100
 	DefaultWeightMsgUpdatePrices     int = 100
 	DefaultWeightMsgCdp              int = 100
+	DefaultWeightMsgClaimReward      int = 100
 )

app/sim_test.go

@@ -284,4 +284,4 @@ func TestAppStateDeterminism(t *testing.T) {
 			)
 		}
 	}
-}
+}

run_a_bunch_of_sims.sh

@@ -1,5 +0,0 @@
-#!/bin/bash
-
-for i in {1..10}; do
-  go test ./app -run TestAppStateDeterminism -Enabled -Commit -NumBlocks=100 -BlockSize=200 -Seed ${i} -v -timeout 24h
-done

x/cdp/simulation/genesis.go

@@ -32,6 +32,7 @@ func RandomizedGenState(simState *module.SimulationState) {
 			sdk.NewCoin("xrp", sdk.NewInt(int64(simState.Rand.Intn(100000000000)))),
 			sdk.NewCoin("btc", sdk.NewInt(int64(simState.Rand.Intn(500000000)))),
 			sdk.NewCoin("usdx", sdk.NewInt(int64(simState.Rand.Intn(1000000000)))),
+			sdk.NewCoin("ukava", sdk.NewInt(int64(simState.Rand.Intn(500000000000)))),
 		)
 		err := acc.SetCoins(acc.GetCoins().Add(coinsToAdd...))
 		if err != nil {

x/incentive/module.go

@@ -8,6 +8,7 @@ import (
 	"github.com/cosmos/cosmos-sdk/codec"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/module"
+	"github.com/cosmos/cosmos-sdk/x/auth"
 	sim "github.com/cosmos/cosmos-sdk/x/simulation"
 	"github.com/gorilla/mux"
 	"github.com/kava-labs/kava/x/incentive/client/cli"
@@ -90,23 +91,25 @@ func (AppModuleBasic) ProposalContents(_ module.SimulationState) []sim.WeightedP
 }
 
 // WeightedOperations returns the all the bep3 module operations with their respective weights.
-func (am AppModule) WeightedOperations(_ module.SimulationState) []sim.WeightedOperation {
-	return nil
+func (am AppModule) WeightedOperations(simState module.SimulationState) []sim.WeightedOperation {
+	return simulation.WeightedOperations(simState.AppParams, simState.Cdc, am.accountKeeper, am.supplyKeeper, am.keeper)
 }
 
 // AppModule implements the sdk.AppModule interface.
 type AppModule struct {
 	AppModuleBasic
 
-	keeper       keeper.Keeper
-	supplyKeeper types.SupplyKeeper
+	keeper        Keeper
+	accountKeeper auth.AccountKeeper
+	supplyKeeper  SupplyKeeper
 }
 
 // NewAppModule creates a new AppModule object
-func NewAppModule(keeper keeper.Keeper, supplyKeeper types.SupplyKeeper) AppModule {
+func NewAppModule(keeper Keeper, accountKeeper auth.AccountKeeper, supplyKeeper SupplyKeeper) AppModule {
 	return AppModule{
 		AppModuleBasic: AppModuleBasic{},
 		keeper:         keeper,
+		accountKeeper:  accountKeeper,
 		supplyKeeper:   supplyKeeper,
 	}
 }

x/incentive/simulation/decoder.go

@@ -1,12 +1,50 @@
 package simulation
 
 import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"time"
+
 	"github.com/cosmos/cosmos-sdk/codec"
 	"github.com/tendermint/tendermint/libs/kv"
+
+	"github.com/kava-labs/kava/x/incentive/types"
 )
 
-// DecodeStore unmarshals the KVPair's Value to the corresponding incentive type
+// DecodeStore unmarshals the KVPair's Value to the module's corresponding type
 func DecodeStore(cdc *codec.Codec, kvA, kvB kv.Pair) string {
-	// TODO implement this
-	return ""
+	switch {
+	case bytes.Equal(kvA.Key[:1], types.RewardPeriodKeyPrefix):
+		var rewardPeriodA, rewardPeriodB types.RewardPeriod
+		cdc.MustUnmarshalBinaryLengthPrefixed(kvA.Value, &rewardPeriodA)
+		cdc.MustUnmarshalBinaryLengthPrefixed(kvB.Value, &rewardPeriodB)
+		return fmt.Sprintf("%v\n%v", rewardPeriodA, rewardPeriodB)
+
+	case bytes.Equal(kvA.Key[:1], types.ClaimPeriodKeyPrefix):
+		var claimPeriodA, claimPeriodB types.ClaimPeriod
+		cdc.MustUnmarshalBinaryLengthPrefixed(kvA.Value, &claimPeriodA)
+		cdc.MustUnmarshalBinaryLengthPrefixed(kvB.Value, &claimPeriodB)
+		return fmt.Sprintf("%v\n%v", claimPeriodA, claimPeriodB)
+
+	case bytes.Equal(kvA.Key[:1], types.ClaimKeyPrefix):
+		var claimA, claimB types.Claim
+		cdc.MustUnmarshalBinaryLengthPrefixed(kvA.Value, &claimA)
+		cdc.MustUnmarshalBinaryLengthPrefixed(kvB.Value, &claimB)
+		return fmt.Sprintf("%v\n%v", claimA, claimB)
+
+	case bytes.Equal(kvA.Key[:1], types.NextClaimPeriodIDPrefix):
+		claimPeriodIDA := binary.BigEndian.Uint64(kvA.Value)
+		claimPeriodIDB := binary.BigEndian.Uint64(kvB.Value)
+		return fmt.Sprintf("%d\n%d", claimPeriodIDA, claimPeriodIDB)
+
+	case bytes.Equal(kvA.Key[:1], types.PreviousBlockTimeKey):
+		var timeA, timeB time.Time
+		cdc.MustUnmarshalBinaryLengthPrefixed(kvA.Value, &timeA)
+		cdc.MustUnmarshalBinaryLengthPrefixed(kvB.Value, &timeB)
+		return fmt.Sprintf("%s\n%s", timeA, timeB)
+
+	default:
+		panic(fmt.Sprintf("invalid %s key prefix %X", types.ModuleName, kvA.Key[:1]))
+	}
 }

x/incentive/simulation/decoder_test.go

@@ -0,0 +1,65 @@
+package simulation
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/cosmos/cosmos-sdk/codec"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/stretchr/testify/require"
+	"github.com/tendermint/tendermint/libs/kv"
+
+	"github.com/kava-labs/kava/x/incentive/types"
+)
+
+func makeTestCodec() (cdc *codec.Codec) {
+	cdc = codec.New()
+	sdk.RegisterCodec(cdc)
+	types.RegisterCodec(cdc)
+	return
+}
+
+func TestDecodeDistributionStore(t *testing.T) {
+	cdc := makeTestCodec()
+
+	// Set up RewardPeriod, ClaimPeriod, Claim, and previous block time
+	rewardPeriod := types.NewRewardPeriod("btc", time.Now().UTC(), time.Now().Add(time.Hour*1).UTC(),
+		sdk.NewCoin("ukava", sdk.NewInt(10000000000)), time.Now().Add(time.Hour*2).UTC(), time.Duration(time.Hour*2))
+	claimPeriod := types.NewClaimPeriod("btc", 1, time.Now().Add(time.Hour*24).UTC(), time.Duration(time.Hour*24))
+	addr, _ := sdk.AccAddressFromBech32("kava15qdefkmwswysgg4qxgqpqr35k3m49pkx2jdfnw")
+	claim := types.NewClaim(addr, sdk.NewCoin("ukava", sdk.NewInt(1000000)), "bnb", 1)
+	prevBlockTime := time.Now().Add(time.Hour * -1).UTC()
+
+	kvPairs := kv.Pairs{
+		kv.Pair{Key: types.RewardPeriodKeyPrefix, Value: cdc.MustMarshalBinaryLengthPrefixed(&rewardPeriod)},
+		kv.Pair{Key: types.ClaimPeriodKeyPrefix, Value: cdc.MustMarshalBinaryLengthPrefixed(&claimPeriod)},
+		kv.Pair{Key: types.ClaimKeyPrefix, Value: cdc.MustMarshalBinaryLengthPrefixed(&claim)},
+		kv.Pair{Key: types.NextClaimPeriodIDPrefix, Value: sdk.Uint64ToBigEndian(10)},
+		kv.Pair{Key: []byte(types.PreviousBlockTimeKey), Value: cdc.MustMarshalBinaryLengthPrefixed(prevBlockTime)},
+		kv.Pair{Key: []byte{0x99}, Value: []byte{0x99}},
+	}
+
+	tests := []struct {
+		name        string
+		expectedLog string
+	}{
+		{"RewardPeriod", fmt.Sprintf("%v\n%v", rewardPeriod, rewardPeriod)},
+		{"ClaimPeriod", fmt.Sprintf("%v\n%v", claimPeriod, claimPeriod)},
+		{"Claim", fmt.Sprintf("%v\n%v", claim, claim)},
+		{"NextClaimPeriodID", "10\n10"},
+		{"PreviousBlockTime", fmt.Sprintf("%v\n%v", prevBlockTime, prevBlockTime)},
+		{"other", ""},
+	}
+	for i, tt := range tests {
+		i, tt := i, tt
+		t.Run(tt.name, func(t *testing.T) {
+			switch i {
+			case len(tests) - 1:
+				require.Panics(t, func() { DecodeStore(cdc, kvPairs[i], kvPairs[i]) }, tt.name)
+			default:
+				require.Equal(t, tt.expectedLog, DecodeStore(cdc, kvPairs[i], kvPairs[i]), tt.name)
+			}
+		})
+	}
+}

x/incentive/simulation/genesis.go

@@ -0,0 +1,140 @@
+package simulation
+
+import (
+	"fmt"
+	"math/rand"
+	"time"
+
+	"github.com/cosmos/cosmos-sdk/codec"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/types/module"
+	authexported "github.com/cosmos/cosmos-sdk/x/auth/exported"
+	"github.com/cosmos/cosmos-sdk/x/simulation"
+
+	"github.com/kava-labs/kava/x/incentive/types"
+)
+
+var (
+	CollateralDenoms    = [3]string{"bnb", "xrp", "btc"}
+	RewardDenom         = "ukava"
+	MaxTotalAssetReward = sdk.NewInt(1000000000)
+)
+
+// RandomizedGenState generates a random GenesisState for incentive module
+func RandomizedGenState(simState *module.SimulationState) {
+	params := genParams(simState.Rand)
+	rewardPeriods := genRewardPeriods(simState.Rand, simState.GenTimestamp, params.Rewards)
+	claimPeriods := genClaimPeriods(rewardPeriods)
+	claimPeriodIDs := genNextClaimPeriodIds(claimPeriods)
+
+	// New genesis state holds valid, linked reward periods, claim periods, and claim period IDs
+	incentiveGenesis := types.NewGenesisState(params, types.DefaultPreviousBlockTime,
+		rewardPeriods, claimPeriods, types.Claims{}, claimPeriodIDs)
+	if err := incentiveGenesis.Validate(); err != nil {
+		panic(err)
+	}
+
+	fmt.Printf("Selected randomly generated %s parameters:\n%s\n", types.ModuleName, codec.MustMarshalJSONIndent(simState.Cdc, incentiveGenesis))
+	simState.GenState[types.ModuleName] = simState.Cdc.MustMarshalJSON(incentiveGenesis)
+}
+
+// genParams generates random rewards and is active by default
+func genParams(r *rand.Rand) types.Params {
+	params := types.NewParams(true, genRewards(r))
+	if err := params.Validate(); err != nil {
+		panic(err)
+	}
+	return params
+}
+
+// genRewards generates rewards for each specified collateral type
+func genRewards(r *rand.Rand) types.Rewards {
+	var rewards types.Rewards
+	for _, denom := range CollateralDenoms {
+		active := true
+		// total reward is in range (half max total reward, max total reward)
+		amount := simulation.RandIntBetween(r, int(MaxTotalAssetReward.Int64()/2), int(MaxTotalAssetReward.Int64()))
+		totalRewards := sdk.NewInt64Coin(RewardDenom, int64(amount))
+		// generate a random number of hours between 6-48 to use for reward's times
+		numbHours := simulation.RandIntBetween(r, 6, 48)
+		duration := time.Duration(time.Hour * time.Duration(numbHours))
+		timeLock := time.Duration(time.Hour * time.Duration(numbHours/2)) // half as long as duration
+		claimDuration := time.Hour * time.Duration(numbHours*2)           // twice as long as duration
+		reward := types.NewReward(active, denom, totalRewards, duration, timeLock, claimDuration)
+		rewards = append(rewards, reward)
+	}
+	return rewards
+}
+
+// genRewardPeriods generates chronological reward periods for each given reward type
+func genRewardPeriods(r *rand.Rand, timestamp time.Time, rewards types.Rewards) types.RewardPeriods {
+	var rewardPeriods types.RewardPeriods
+	for _, reward := range rewards {
+		rewardPeriodStart := timestamp
+		for i := 10; i >= simulation.RandIntBetween(r, 2, 9); i-- {
+			// Set up reward period parameters
+			start := rewardPeriodStart
+			end := start.Add(reward.Duration).UTC()
+			baseRewardAmount := reward.AvailableRewards.Amount.Quo(sdk.NewInt(100)) // base period reward is 1/100 total reward
+			// Earlier periods have larger rewards
+			amount := sdk.NewCoin(reward.Denom, baseRewardAmount.Mul(sdk.NewInt(int64(i))))
+			claimEnd := end.Add(reward.ClaimDuration)
+			claimTimeLock := reward.TimeLock
+			// Create reward period and append to array
+			rewardPeriod := types.NewRewardPeriod(reward.Denom, start, end, amount, claimEnd, claimTimeLock)
+			rewardPeriods = append(rewardPeriods, rewardPeriod)
+			// Update start time of next reward period
+			rewardPeriodStart = end
+		}
+	}
+	return rewardPeriods
+}
+
+// genClaimPeriods loads valid claim periods for an array of reward periods
+func genClaimPeriods(rewardPeriods types.RewardPeriods) types.ClaimPeriods {
+	denomRewardPeriodsCount := make(map[string]uint64)
+	var claimPeriods types.ClaimPeriods
+	for _, rewardPeriod := range rewardPeriods {
+		// Increment reward period count for this denom (this is our claim period's ID)
+		denom := rewardPeriod.Denom
+		numbRewardPeriods := denomRewardPeriodsCount[denom] + 1
+		denomRewardPeriodsCount[denom] = numbRewardPeriods
+		// Set end and timelock from the associated reward period
+		end := rewardPeriod.ClaimEnd
+		claimTimeLock := rewardPeriod.ClaimTimeLock
+		// Create the new claim period for this reward period
+		claimPeriod := types.NewClaimPeriod(denom, numbRewardPeriods, end, claimTimeLock)
+		claimPeriods = append(claimPeriods, claimPeriod)
+	}
+	return claimPeriods
+}
+
+// genNextClaimPeriodIds returns an array of the most recent claim period IDs for each denom
+func genNextClaimPeriodIds(cps types.ClaimPeriods) types.GenesisClaimPeriodIDs {
+	// Build a map of the most recent claim periods by denom
+	mostRecentClaimPeriodByDenom := make(map[string]uint64)
+	for _, cp := range cps {
+		if cp.ID > mostRecentClaimPeriodByDenom[cp.Denom] {
+			mostRecentClaimPeriodByDenom[cp.Denom] = cp.ID
+		}
+	}
+	// Write map contents to an array of GenesisClaimPeriodIDs
+	var claimPeriodIDs types.GenesisClaimPeriodIDs
+	for key, value := range mostRecentClaimPeriodByDenom {
+		claimPeriodID := types.GenesisClaimPeriodID{Denom: key, ID: value}
+		claimPeriodIDs = append(claimPeriodIDs, claimPeriodID)
+	}
+	return claimPeriodIDs
+}
+
+// In a list of accounts, replace the first account found with the same address. If not found, append the account.
+func replaceOrAppendAccount(accounts []authexported.GenesisAccount, acc authexported.GenesisAccount) []authexported.GenesisAccount {
+	newAccounts := accounts
+	for i, a := range accounts {
+		if a.GetAddress().Equals(acc.GetAddress()) {
+			newAccounts[i] = acc
+			return newAccounts
+		}
+	}
+	return append(newAccounts, acc)
+}

x/incentive/simulation/operations.go

@@ -0,0 +1,146 @@
+package simulation
+
+import (
+	"fmt"
+	"math/rand"
+
+	"github.com/cosmos/cosmos-sdk/baseapp"
+	"github.com/cosmos/cosmos-sdk/codec"
+	"github.com/cosmos/cosmos-sdk/simapp/helpers"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/x/auth"
+	authexported "github.com/cosmos/cosmos-sdk/x/auth/exported"
+	"github.com/cosmos/cosmos-sdk/x/auth/vesting"
+	"github.com/cosmos/cosmos-sdk/x/simulation"
+
+	appparams "github.com/kava-labs/kava/app/params"
+	"github.com/kava-labs/kava/x/incentive/keeper"
+	"github.com/kava-labs/kava/x/incentive/types"
+	"github.com/kava-labs/kava/x/kavadist"
+)
+
+// Simulation operation weights constants
+const (
+	OpWeightMsgClaimReward = "op_weight_msg_claim_reward"
+)
+
+// WeightedOperations returns all the operations from the module with their respective weights
+func WeightedOperations(
+	appParams simulation.AppParams, cdc *codec.Codec, ak auth.AccountKeeper, sk types.SupplyKeeper, k keeper.Keeper,
+) simulation.WeightedOperations {
+	var weightMsgClaimReward int
+
+	appParams.GetOrGenerate(cdc, OpWeightMsgClaimReward, &weightMsgClaimReward, nil,
+		func(_ *rand.Rand) {
+			weightMsgClaimReward = appparams.DefaultWeightMsgClaimReward
+		},
+	)
+
+	return simulation.WeightedOperations{
+		simulation.NewWeightedOperation(
+			weightMsgClaimReward,
+			SimulateMsgClaimReward(ak, sk, k),
+		),
+	}
+}
+
+// SimulateMsgClaimReward generates a MsgClaimReward
+func SimulateMsgClaimReward(ak auth.AccountKeeper, sk types.SupplyKeeper, k keeper.Keeper) simulation.Operation {
+	return func(
+		r *rand.Rand, app *baseapp.BaseApp, ctx sdk.Context, accs []simulation.Account, chainID string,
+	) (simulation.OperationMsg, []simulation.FutureOperation, error) {
+
+		// Load only account types that can claim rewards
+		var accounts []authexported.Account
+		validAccounts := make(map[string]bool)
+		for _, acc := range accs {
+			account := ak.GetAccount(ctx, acc.Address)
+			switch account.(type) {
+			case *vesting.PeriodicVestingAccount, *auth.BaseAccount: // Valid: BaseAccount, PeriodicVestingAccount
+				accounts = append(accounts, account)
+				validAccounts[account.GetAddress().String()] = true
+				break
+			default: // Invalid: ValidatorVestingAccount, DelayedVestingAccount, ContinuousVestingAccount
+				break
+			}
+		}
+
+		// Load open claims and shuffle them to randomize
+		openClaims := types.Claims{}
+		k.IterateClaims(ctx, func(claim types.Claim) bool {
+			openClaims = append(openClaims, claim)
+			return false
+		})
+		r.Shuffle(len(openClaims), func(i, j int) {
+			openClaims[i], openClaims[j] = openClaims[j], openClaims[i]
+		})
+
+		kavadistMacc := sk.GetModuleAccount(ctx, kavadist.KavaDistMacc)
+		kavadistBalance := kavadistMacc.SpendableCoins(ctx.BlockTime())
+
+		// Find address that has a claim of the same reward denom, then confirm it's distributable
+		claimer, claim, found := findValidAccountClaimPair(accs, openClaims, func(acc simulation.Account, claim types.Claim) bool {
+			if validAccounts[acc.Address.String()] { // Address must be valid type
+				if claim.Owner.Equals(acc.Address) { // Account must be claim owner
+					allClaims, found := k.GetClaimsByAddressAndDenom(ctx, claim.Owner, claim.Denom)
+					if found { // found should always be true
+						var rewards sdk.Coins
+						for _, individualClaim := range allClaims {
+							rewards = rewards.Add(individualClaim.Reward)
+						}
+						if rewards.AmountOf(claim.Reward.Denom).IsPositive() { // Can't distribute 0 coins
+							// Validate that kavadist module has enough coins to distribute rewards
+							if kavadistBalance.AmountOf(claim.Reward.Denom).GTE(rewards.AmountOf(claim.Reward.Denom)) {
+								return true
+							}
+						}
+					}
+				}
+			}
+			return false
+		})
+		if !found {
+			return simulation.NewOperationMsgBasic(types.ModuleName,
+				"no-operation (no accounts currently have fulfillable claims)", "", false, nil), nil, nil
+		}
+
+		claimerAcc := ak.GetAccount(ctx, claimer.Address)
+		if claimerAcc == nil {
+			return simulation.NoOpMsg(types.ModuleName), nil, fmt.Errorf("couldn't find account %s", claimer.Address)
+		}
+
+		msg := types.NewMsgClaimReward(claimer.Address, claim.Denom)
+
+		tx := helpers.GenTx(
+			[]sdk.Msg{msg},
+			sdk.NewCoins(),
+			helpers.DefaultGenTxGas,
+			chainID,
+			[]uint64{claimerAcc.GetAccountNumber()},
+			[]uint64{claimerAcc.GetSequence()},
+			claimer.PrivKey,
+		)
+
+		_, result, err := app.Deliver(tx)
+		if err != nil {
+			// to aid debugging, add the stack trace to the comment field of the returned opMsg
+			return simulation.NewOperationMsg(msg, false, fmt.Sprintf("%+v", err)), nil, err
+		}
+
+		// to aid debugging, add the result log to the comment field
+		return simulation.NewOperationMsg(msg, true, result.Log), nil, nil
+	}
+}
+
+// findValidAccountClaimPair finds an account and reward claim for which the callback func returns true
+func findValidAccountClaimPair(accounts []simulation.Account, claims types.Claims,
+	cb func(simulation.Account, types.Claim) bool) (simulation.Account, types.Claim, bool) {
+	for _, claim := range claims {
+		for _, acc := range accounts {
+			if isValid := cb(acc, claim); isValid {
+				return acc, claim, true
+			}
+		}
+	}
+	return simulation.Account{}, types.Claim{}, false
+}

x/incentive/simulation/params.go

@@ -1,14 +1,40 @@
 package simulation
 
 import (
+	"fmt"
 	"math/rand"
 
 	"github.com/cosmos/cosmos-sdk/x/simulation"
+	"github.com/kava-labs/kava/x/incentive/types"
 )
 
-// ParamChanges defines the parameters that can be modified by param change proposals
-// on the simulation
-func ParamChanges(r *rand.Rand) []simulation.ParamChange {
-	// TODO implement this
-	return []simulation.ParamChange{}
+const (
+	keyActive  = "Active"
+	keyRewards = "Rewards"
+)
+
+// genActive generates active bool with 80% chance of true
+func genActive(r *rand.Rand) bool {
+	threshold := 80
+	value := simulation.RandIntBetween(r, 1, 100)
+	if value > threshold {
+		return false
+	}
+	return true
+}
+
+// ParamChanges defines the parameters that can be modified by param change proposals
+func ParamChanges(r *rand.Rand) []simulation.ParamChange {
+	return []simulation.ParamChange{
+		simulation.NewSimParamChange(types.ModuleName, keyActive,
+			func(r *rand.Rand) string {
+				return fmt.Sprintf("\"%t\"", genActive(r))
+			},
+		),
+		simulation.NewSimParamChange(types.ModuleName, keyRewards,
+			func(r *rand.Rand) string {
+				return fmt.Sprintf("\"%v\"", genRewards(r))
+			},
+		),
+	}
 }

x/incentive/simulation/simulation.go

@@ -1,22 +0,0 @@
-package simulation
-
-import (
-	"fmt"
-
-	"github.com/cosmos/cosmos-sdk/codec"
-	"github.com/cosmos/cosmos-sdk/types/module"
-
-	"github.com/kava-labs/kava/x/incentive/types"
-)
-
-// RandomizedGenState generates a random GenesisState for cdp
-func RandomizedGenState(simState *module.SimulationState) {
-
-	// TODO implement this fully
-	// - randomly generating the genesis params
-	// - overwriting with genesis provided to simulation
-	genesis := types.DefaultGenesisState()
-
-	fmt.Printf("Selected randomly generated %s parameters:\n%s\n", types.ModuleName, codec.MustMarshalJSONIndent(simState.Cdc, genesis))
-	simState.GenState[types.ModuleName] = simState.Cdc.MustMarshalJSON(genesis)
-}

x/kavadist/simulation/genesis.go

@@ -14,10 +14,11 @@ import (
 )
 
 // SecondsPerYear is the number of seconds in a year
-const SecondsPerYear = 31536000
-
-// BaseAprPadding prevents the calculated SPR inflation rate from being 0.0
-const BaseAprPadding = "0.000000000100000000"
+const (
+	SecondsPerYear = 31536000
+	// BaseAprPadding sets the minimum inflation to the calculated SPR inflation rate from being 0.0
+	BaseAprPadding = "0.000000003022265980"
+)
 
 // RandomizedGenState generates a random GenesisState for kavadist module
 func RandomizedGenState(simState *module.SimulationState) {
@@ -46,8 +47,8 @@ func genRandomPeriods(r *rand.Rand, timestamp time.Time) types.Periods {
 	numPeriods := simulation.RandIntBetween(r, 1, 10)
 	periodStart := timestamp
 	for i := 0; i < numPeriods; i++ {
-		// set periods to be between 2 weeks and 2 years
-		durationMultiplier := simulation.RandIntBetween(r, 14, 104)
+		// set periods to be between 1-3 days
+		durationMultiplier := simulation.RandIntBetween(r, 1, 3)
 		duration := time.Duration(int64(24*durationMultiplier)) * time.Hour
 		periodEnd := periodStart.Add(duration)
 		inflation := genRandomInflation(r)
@@ -59,13 +60,14 @@ func genRandomPeriods(r *rand.Rand, timestamp time.Time) types.Periods {
 }
 
 func genRandomInflation(r *rand.Rand) sdk.Dec {
-	// If sim.RandomDecAmount returns 0 (happens frequently by design), add BaseAprPadding
+	// If sim.RandomDecAmount is less than base apr padding, add base apr padding
+	aprPadding, _ := sdk.NewDecFromStr(BaseAprPadding)
 	extraAprInflation := simulation.RandomDecAmount(r, sdk.MustNewDecFromStr("0.25"))
-	for extraAprInflation.Equal(sdk.ZeroDec()) {
-		extraAprInflation = extraAprInflation.Add(sdk.MustNewDecFromStr(BaseAprPadding))
+	for extraAprInflation.LT(aprPadding) {
+		extraAprInflation = extraAprInflation.Add(aprPadding)
 	}
-
 	aprInflation := sdk.OneDec().Add(extraAprInflation)
+
 	// convert APR inflation to SPR (inflation per second)
 	inflationSpr, err := approxRoot(aprInflation, uint64(SecondsPerYear))
 	if err != nil {